问题 多选题

关于加速度,下述说法中正确的是(  )

A.加速度的大小与速度的大小无必然联系

B.加速度的方向与速度的方向可能相同,也可能相反

C.加速度很大时物体速度可能很小

D.加速度大的物体速度变化一定很大

答案

A、加速度表示物体速度变化的快慢,由物体的合力与质量共同决定,与速度没有直接的关系.故A正确.

    B、加速度方向与速度变化量的方向相同,加速直线运动,两者方向相同,减速直线运动,两者方向相反.故B正确.

    C、由于加速度与速度无关,加速度很大时物体速度可能很小,比如火箭刚点火瞬间.故C正确.

    D、加速度的大小等于物体单位时间内速度的变化,加速度大,速度变化量不一定很大,还取决于时间.故D错误.

故选ABC

阅读理解

Two Chinese farmers who became an overnight sensation(轰动)when their heart-rendingversion of a famous pop song appeared on the Internet took to the stage in front of thousands offans in Shanghai last Saturday.

Wang Xu, 44,and Liu Gang, 29, sang “In the Spring" alongside the song's star composerWang Feng, in front of about 80,000 people at the Shanghai Stadium.

The audience buzzed with excitement and let out deafening cheers, the moment as theywere introduced on the stage and then when Liu started the first sentence of their parts of thesong.

The two migrant workers became stars after singing the tearjerker(催人泪下的)songduring an evening drinking session in a 6-square-meter rented room in a late August evening. Afriend recorded the performance on a cell phone and posted it on the Internet.

“If someday I am dead, please bury me in the spring," they sing. Wang's penetrating chorus,delivered with his eyes closed, has moved thousands to tears.

Wang and Liu consider the song a true portrait of lower-class groups like themselves."With no credit card, no girlfriend, or a home with hot water, but only a guitar, I am singinghappily, on streets, under bridges or in wild country, though nobody pays attention to themusic," they sing.

To support his wife and two sons, Wang came to Beijing in 2000 from the countryside andhas worked as a boiler man, and street peddler, before becoming a medical warehouse keeper,with a monthly pay of around 1,500 yuan. Little is left after he pays 600 yuan for rent and buysfood.

Liu came to Beijing in 2002. “I wanted to try my luck in the big city,,,he said. He hadworked as a guard, roadside peddler, and porter, but never had a stable job. Street performingwas his main income, even after he married and became a father three years ago.

Wang and Liu are still uncertain where their fame will lead. Wang has started learning touse a computer. They even have a microblog(微博)account to communicate with fans.

小题1:Wang Xu and Liu Gang first became nationally known after______.

A.they sang the song “In the Spring" with a star composer Wang Feng

B.the video of them singing “In the Spring" was posted on the Internet

C.they sang on streets and under bridges

D.they started their microblog小题2:People like Wang and Liu's version of “In the Spring" because ______ .

A.they sang the song better than other singers

B.they were introduced to the public by the song writer himself

C.it was specially composed for them two

D.it is a heartfelt expression of the two singers as migrant workers小题3:It can be inferred from the passage that   ______.

A.migrant workers' conditions will be improved soon

B.they will learn to write songs on computers

C.a song showing people's real life and feelings is more likely to be accepted

D.singers for migrant workers are more likely to become popular小题4:The best possible title for the passage is______.

A.Internet Farmer Stars Make Stage Appearance

B.“In the Spring"—A Touching Song

C.A Successful Internet Performance

D.No Pains, No Gains

单项选择题 A1型题